Pollution Protection Systems Mumbai Pvt. Mumbai, Maharashtra

Certified for Intrinsically safe as per I.S. 5780 Certified for performance as per IS 9000 (part V).

Sensors used for Oxygen measurement are current generators, producing a current that is proportional to volume concentration of gas. The central feature is the gaseous diffusion barrier, which limits the flow of gas in to the sensor and ensures it is not swamped. This ensures that each sensor has long life and excellent stability. In addition these sensors are relatively not affected by changes in ambient condition. All Oxygen Sensors are self powered, diffusion limited, metal air battery type comprising of anode electrolyte and an air-cathode.

These are micro fuel cells, designed to be maintenance free and stable over long periods of time. This is a three electrode sensor as explained earlier. The Electro chemical sensor has three electrodes - a sensing counter and reference separated by a thin layer of electrolyte. Gas diffuses in to the sensor to be oxidized or reduced at the sensing electrodes. The resulting exchange of electron causes the potential of the electrode to change with respect to the counter. This can be measured by connecting a resister between the electrodes and monitoring the resultant current.

These sensors basically consist of two coils (elements) sensing and reference Combustible Gases are oxidized on the detector (sensing) element and the resulting heat generated on the element increases the temperature and resistance of the coil. No oxidation occurs on the inert reference element so its temperature is unaffected. By placing both elements in a wheat stone bridge circuit, an out-of-balance signal is produced proportional to the concentration of combustible gas. Thus 0-100% LEL (Lower Explosive Limits) could be measured.

All the equipments manufactured by PPS are simple to calibrate. Calibration should be done by using a gas mixture with a concentration of the target gas in the middle of the desired range.